In post-Sep. 11, 2001 terrorist attacks on New York City which has heightened fears of man-made disasters and terrorist acts, it has been envisaged that ships and large vessels may be used to attack and destroy harbors and seafront installations such as oil refineries, chemical plants, etc. or another sea-borne object such as oil rig or a passenger ship. As some of the ships and vessels may be carrying flammable or inflammable materials, such as crude oil or refined petroleum products, they might be hijacked by terrorists and set on course to collide with these targets of attack. If the vessel is large enough, its massive moving mass may create a momentum large enough to cause destruction by sheer collision onto a target.
Accordingly, it is imperative that methods are available for preventing such attacks and that the errant or malfunctioning vessel be quickly controlled and yawed to avoid colliding with the targets or being used as a weapon of massive destruction.
U.S. Pat. No. 6,591,774 discloses a barrier system for protecting ships and harbors from attack by vessels. The barrier system is constructed around the ships or harbor to be defended. The barrier may either be floating on the surface above and/or beneath the surface of the water. When a vessel attempts to force its way through the barrier, the barrier uses the momentum of the vessel against itself by using the forward momentum of the attacking vessel in such a manner as to divert, impede, stop, damage or destroy the vessel. This system however may only be suitable for stopping a small attacking vessel and may not be suitable for arresting, large shipping vessels.
U.S. Pat. No. 6,413,128 discloses a device for changing the direction of travel of a watercraft. The device includes a gondola-like underwater housing having a container favorable in terms of flow outside the hull by the watercraft, and is connected to the hull of the watercraft by a shaft. The change in direction of travel of the watercraft is brought about by a pivoting motor acting on the shaft, and the use of high energy fluid jets in the gondola-like structure. The latter is a permanent device attached to the watercraft to enhance steering at low noise.
U.S. Pat. No. 6,698,374 discloses a tugboat design with a towing installation having a 360° turning to steer and guide a large shipping vessel. There is no disclosure on means of attaching the tow rope to a vessel to be towed, especially a large vessel such as a hijacked one, as access to the vessel would be denied.
It is therefore desirable that a method be provided to effectively intercept an errant or malfunctioned vessel from crashing into a seaside installation or sea-borne target of terrorist attacks or mishaps resulting from vessel malfunction. As some of these vessels may be of a huge size and tonnage, and carrying flammable cargo such as petroleum products, it is essential that any such method is effective in changing the course of direction of the vessel as quickly and in the shortest distance as possible. Preferably, such methods are able to achieve a turning radius of 2 km.
Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Singapore or elsewhere on or before the priority date of the disclosure and claims herein. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicant and does not constitute any admission as to the correctness of the dates or contents of these documents.